What to expect from 'Age of Ultron'

The Avengers are back, and they've got some new friends — and foes

The follow-up to 2012's massive "The Avengers" promises to be even more gargantuan, with new superheroes, more story to tell and a one really shiny, really deadly villain. So here's what you need to know going into "Avengers: Age of Ultron."

1. Black Widow did not do her own stunts.

"I don’t think you’re allowed to ride a motorcycle when you’re still pregnant," Scarlett Johansson says. "I embarrassingly rode some sort of a mechanical bull type of motorcycle which goes nowhere and doesn’t look cool at all. But we had some very professional and amazing motocross work being done that makes Black Widow look like a total bad-ass."

2. Iron Man didn't do any meddling.

According to franchise star Robert Downey Jr. — who kicked off the whole Marvel Cinematic Universe deal seven years ago with "Iron Man" — he didn't have to do any meddling with the script this time around. "I read [Joss Whedon's] script, I said, 'I think this is great.' [Marvel honcho] Kevin [Feige] said, 'You never say that, you can't mean that,'" Downey recalls. "I thought it was a Swiss watch to begin. So rather than dig in my heels and try to rewrite every scene … I just showed up and it turned out great."

3. It nearly killed Joss Whedon.

“There’s like 47 of these people, and I really didn’t think that through. And I regret very much doing this at all," jokes the writer-director, who was under tremendous pressure to follow up the critical and financial success of the first film. "At some point during the editing process, I could not have told you who they were, who I was, what movie I was making. I got so lost in it. But, I think it all came together."

4. James Spader got a crash-course in Marvel movie-making.

The "Blacklist" star embodies the chillingly evil robot Ultron bent on destroying the Avengers — and humanity in general. And he barely had any time to get into character. "I really didn’t have any idea what was happening at all. I really was just trying to hold on and stay on the train that was moving very, very quickly," Spader says. "Luckily I’d had some conversations with Joss and one fantastic meal with a whole bunch of wine to figure out who this guy was."

5. There are secrets the cast can't divulge.

Mark Ruffalo, who stars as the Hulk, says their studio bosses have ways of making them not reveal spoilers. "You know, we have a Marvel app on our iPhones and if you say something wrong it literally shocks you," he says. OK, maybe they don't really, but we wouldn't put it past them. Speaking of secrets …

6. Hawkeye speaks!

Jeremy Renner's Hawkeye admittedly didn't get a whole ton of screen time in the first "Avengers," so he gets a bit more attention this time around. "I speak in this movie, which is awesome," Renner jokes. "I understood Hawkeye in the sense of he's a human just with a high skill set, so I could tap into that, and I feel like I got to explore a little bit more of that, even outside the skill set, and I thought that was a really, really endearing and thoughtful sort of secret that he had and I’m excited to kind of see where that goes."

7. Jarvis comes to life!

One of the new characters on display is the much-anticipated Vision, played by Paul Bettany, who had previously only served as the voice of Tony Stark's computer system, Jarvis. "The main difference is that I have to show up," Bettany says. "The great thing is being able to work with all these creative and talented people. However, I now also have to show up at press junkets, so everything’s a double edged sword."